Conventional approaches for comparator designs implement hysteresis utilizing a form of positive feedback. Traditionally, hysteresis that is incorporated into a design using positive feedback does not provide accurately or efficiently controlled hysteresis. Hysteresis is the measure for a comparator for which an input threshold changes as a function of the input (or output) level. More specifically, when the input passes the input threshold, the output changes state and the input threshold is subsequently reduced so that the input must return beyond the initial input threshold before the output of the comparator changes state again.
Such conventional implementations are dependent on temperature and process variations resulting in an uncontrolled amount of hysteresis. An example of one conventional approach can be found in U.S. Pat. No. 4,072,870 entitled “Comparison circuit having programmable hysteresis”, which is hereby incorporated by reference in its entirety. The conventional approach of U.S. Pat. No. 4,072,870 implements a steering current through a resistor to produce symmetrical hysteresis. However, the conventional approach does not present accurate or efficiently controlled hysteresis.